Harpoon cannon
（重定向自Harpoon gun）
A harpoon cannon is a whaling implement developed in the late 19th century and most used in the 20th century. It would be mounted on the bow of a whale catcher, where it could be easily aimed with a wide field of view at the target. Powered by black powder and later, smokeless powder, it would generally fire a large steel harpoon, either solid steel (cold harpoon) or fitted with an exploding black powder, or later, penthrite (PETN) grenade.